Power wheelchairs are known and have been the subject of increasing development efforts to provide handicapped and disabled persons with independent mobility to assist handicapped and disabled persons in leading more normal lives.
Power wheelchairs known heretofore have, for the most part, resembled conventional, manual wheelchairs; indeed, many such power wheelchairs have merely been conventional wheelchairs equipped with motors. Use of such power wheelchairs sometimes results in the user feeling a stigma associated therewith in that unthoughtful persons may view and even speak to the power wheelchair user in a quizzical or even offensive manner.
Known power wheelchairs suffer in that they tend to be large and are not particularly maneuverable. These large, difficult to maneuver power wheelchairs present difficulties for the power wheelchair user in navigating within conventional dwellings which have not been modified to accommodate such conventional power wheelchairs.
Typical conventional rear wheel drive power wheelchairs, which are little more than manual wheelchairs equipped with motors, have turning circles of about 72 inches in diameter, whereas typical front wheel drive power wheelchairs have, for the most part, turning circles in the neighborhood of 52 inches in diameter. These turning circles are too big for the user of a conventional power wheelchair to reverse the wheelchair direction by turning the wheelchair around within a corridor or hallway of a conventional office building or most homes.
Power wheelchairs with two drive motors are known; one is illustrated in U.S. Pat. No. 5,540,297. Other power wheelchairs are disclosed in U.S. Pat. Nos. 4,513,832; 4,538,857; 5,094,310; 5,145,020 and 5,366,037.
Front wheel drive power wheelchairs are sold by Permobile, Inc. in Woburn, Mass. and typically have the driving front wheels at the extreme forward end of the vehicle chassis thereby requiring substantial space in order to turn the front wheel drive power wheelchair because the axis of rotation of the chair, upon turning, is between the drive wheel axes which are at the extreme forward end of the chair.
Foldable power rear wheel drive wheelchairs are also known, having been developed by converting conventional folding wheelchairs into powered folding wheelchairs by incorporation of drive motors into the conventional folding wheelchairs. Such conventional folding wheelchairs are typically difficult to fold in that an "X" folding mechanism is utilized having sleeves sliding along tubular members in a vertical direction as the two halves or sides of the folding wheelchair frame move towards one another. The "X" members terminate in the sleeves which slide up and down along vertical members of the side frames. Typically, the sleeves tend to bind as the sleeves endeavor to slide along the vertical members; such binding makes it difficult to fold and unfold conventional folding power wheelchairs.